Self-opening die-head



W. C. HAFEMEISTER. SELF OPENING DIE HEAD. APPLICATION FILED OCT. I9. 1918.

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W. C. HAFEMEISTER.

SELF OPENING DIE HEAD.

APPLICATION FILED OCT. 19, I9I8.

'1,394,549@ Patented Oct. 25, 1921. I7 28 26 3 SHEETS-SHEEE 2.

D/YTTOZE/VEVQ.

W. C. HAFEMEISTER.

SELF OPENING DIE HEAD.

APPLICATION FILED OCT. 19, 1918.

1,39%,5490 v Patented Oct. 25, 1921.

3 SHEETSSHEET 3.

FATE @FFEE.

-WILLIAM C. HAFEMEISTER, OF CLEVELAND, OHIO, ASSIGNOR TO THE METAL PARTS MANUFACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

SELF-OPENING DIE-HEAD.

Application filed October 19, 1918.

T 0 all whom it may cmwern.

Be it known that I, \VILLIAM C'. Harn- MEISTER, a citizen of the United States, and a resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in Self-Opening Die- Heads, of which the following isa specifica. tion, the principle of the invention being herein explained and the best mode in which I have contemplated applying that invention, so as to distinguish it from other inventions.

The present improved die-head is of the automatic or self-opening type, i. 6. it includes radially movable chasers that, upon completion of the cut, are automatically're tracted a suflicientamount to clear the work. One object of the invention is to so construct a die-head of this type as to enable it to be used on work requiring precision of the highest degree. A further object is to render the head adjustable to work of different diameters without change of dies, chasers of special construction being utilized to this end. The die-headis furthermore of relatively simple and compact construction, the cooperating parts being so arranged that they can be case-hardened, thus practically eliminating wear.

To the'accomplishment of the foregoing and related ends, the invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle oft-he'invention may be used.

In said annexed drawings Figure l is a front elevation of my improved die-head, showing the chasers in their outermost or retracted position; Fig. 2 is an axial section of the head taken on-the line axial section similar to that of Fig. 2, but

showing the relative position of parts when the cliasers are advanced; Figs. 6 and 7 are transverse sections of the head, taken on the Specification of Letters Patent.

Patented Oct. 25, 1921.

Serial No. 258,862.

planes indicated by the lines 6-6 and 7-7, F g. 5; Fig. 8 is a view corresponding to F1g. 4, but showing the position of parts as 111 Fig. 5 (of. line 8-8, Fig. 5) Fig. 9 is an axial section of the head at right angles to that of Fig. 5, as indicated by the line 9-9 on said Fig. 5; Fig. 10 is another axial section of the head taken on the plane indicated by the lines l010, Figs. 6 and 7; Fig. 11 is partly an axial section and partly an elevation of the head, the plane of the sect1on and the position-of the parts being the same as in Fig. 2; Fig. 12 is a side elevation of the body of the head viewing the same from the rear, as illustrated in Figs. 2 and 5; Fig. i8 is a perspective of one of the slides to which the chasers are attached; Fig. 14 is a perspective of a chaser-locating block adjustably mounted in such slide; Fig. 15 is a side elevation of a chaser by itself; and Fig. 16 is a side elevation of a set of such chasers, viewed in the opposite direction.

The central element of the head is a tubular shank l which is designed to be non-rotatably held in the lathe or like machine as preferably of the segmental form as shown in Figs. 4 and 8.. Alined with these lugs are longitudinally extending apertures -i in such enlarged portion of the shank, wherein are contained compression springs 5, the rear ends. of which bear against reciprocable plunger-s 6, that engage with the body or barrel 7 of the head to position the same longitudinally of said shank as will now be described.

Said body or barrel is rotatably mounted upon such enlarged portion of the shank, he-

ing held thereon by means of an annular plate 8 that closes such .body at the rear. The rear endof the body is formed with two oppositely disposed recesses 9 of the shape'shown in Fig. 9, in which the aforesaid lugs 3 on the shank respectively lie. These lugs, when alined with the deeper portions of the recess, permit of limited longitudinal movement of the body relatively to the shank, but hold the former against rotation about the latter, and when the body occupies its extreme advanced position on the shank, said body may rotate a limited amount in one direction or the other, and in such rotated position is held against relative longitudinal movement on the shank. The plungers 6, it will be observed, bear against the plate 8 and so tend at all times to force the body rearwardly as far as the ears that play in the recess 9 will permit.

At its forward end said body is formed with rectangularly intersecting diametral guideways 1U inwhich are held, so as to be movable radially inwardly or outwardly as desired, four die-supporting slides 11 of the form illustrated in perspective in Fig. 13, and in central section in Figs. 2 and The guideways are provided with projecting ribs 13 and the slides with corresponding lateral grooves 14 whereby such slides are thus held in said uideways, as will be readily understood. he outer end of each slide is formed with an enlarged head 15, the outer surface of which is coned to conform with the inner corie surface 16 of a cam-ring 17, that is mounted upon the body 7 so as to have limited longitudinal movement thereon, such slides being secured to said ring by means of segmental plates 18 attached to the inner face of its forwardly extending portion, such plates underlying the heads 15, as best shown in Fig. 7. The result of this connection is to *ause the slides to be retracted when the cam ring is advanced. 6. moved forwardly or to the left, as illustrated in Figs. 2 and 5, and, conversely, to cause said slides to be advanced when said cam-ring isretracted, or, in other words, moved to the right, as illustrated in the figures in question.

The rearwardly extending portion of camring 17 is of somewhat reduced diameter,

and is formed with a series of triangular notches 19 in its rearedge (four in number as shown), and on its outer cylindrical face with a corresponding number of paralleldisposed angular grooves 21 which open into such rear edge.

Rotatably mounted upon the body or barrel of the head, to the rear of the camring just described, is a second ring 25 that is formed on its forward edge with a series or triangular projections 25- corresponding in disposition with the notches 19 in the rear edge of the cam-ring. The second ring 25 is held in proper place longitudinally of the body or barrel by means of an annulus or nut 26 internally threaded to engage the rear end of such body, which is correspondingly threaded. The main portion of this annulus is knurled in order to permit it to be rotated on the barrel, while the forwardly projecting portion thereof is formed with a circumferential groove 27 by means of which an outer cylindrical casing 28 is rotatably attached thereto through the me dium of pins 29 that project inwardly through the rear end of such casing into engagement with such groove. The body of this casing extends forwardly over the ring 25 so as completely to inclose the same, as well as over the rear portion of the camring 17, the forward end of said casing being bored out to snugly'fit over the enlarged forward portion of such cam-ring, towhich the chaser slides are attached as hereinbefore described. Said ring 25 is non-rotatably secured to this casing, and in effect constitutes an integral part thereof in the assembled condition of the head, such attachment being conveniently effected by extending the inner end of a handle 30, which projects radially from the casing, through the same and into a registering aperture 31 in said ring.

A series of hardened balls 32 are inset in the rear face of ring 25 to bear against the forward face of the annulus 26 which is likewise hardened, and other balls 33 are similarly inset in the forward extremities of the angular projections 25 on the front face of said ring, which bear against the rear edge of the cam ring 17, as hereinbefore described, it being understood that such cam ring is likewise case-hardened. This cam ring is further directly connected to the casing throu h the medium of a series of radially inwardly projecting pins 34 in said casing, the inner ends of which engage the angular grooves 21 in said cam ring, as best shown in Fig. 11.

As a result of the connections just de scribed, rotative movement of the casing 28 will obviously serve to advance and retract the cam ring, correspondingly affecting the position of the chaser slides 11. It will'also be obvious that, by rotation of the knurled annulus 26 about the body of the die-head, the position of the casing 28 longitudinally of said body may be adjusted so as to correspondingly vary the normal position of the cam ring, and thus of said slides. This annuulus bears graduations, as shown in Fig. 11, to enable the position of the dies to be determined by simply bringing the proper graduation into register with a fixed point of reference on the casing.

Extending forwardly from the rear en of the body 01' barrel of the head is aseries of circular apertures 40 adapted to receive compression springs (see Fig. 10), such apertures being closed at the rear of the die-head by the annular plate 8 that closes the rear end of such body. Slots 42 are cut through the outer wall of the body or barrel so as to lay open these spring-receiving apertures throughout their intermediate portions, and pins or lugs 43 set into the inner face of the cam ring 17 project through these slots so as to be engaged by the rear ends of the springs. the tendency of which will accordingly he at all times to retract said cam ring relatively to the body. as will be evident. Such body is also provided with a recess. or rather aperture 11. intermediate between two of the spring-containing apertures". of the form clearly shown in Fig. 12. wherein is received a projection or pin 45, preferably of rectangular outline. projecting radially from the forward. enlarged end 2 of the shank 1. 'hen the body or barrel is in its retracted position upon said shank. this pin engages the forward narrower portion of such aperture. whereby the body is ium-rotatably secured to the shank. but in the advanced position of the body the body is free to rotate through a limited arc corresponding with the wider portion of such aperture.

Incidentally to such rotation. the body, carrying with it the ring 25. induces a partial relative rotation of the latter, since the outer end of projection 45 extends into a recess 46 in the inner surface of such ring overlying the aperture 41, and, by engagement with one end or the other of such recess, correspondingly limits rotation of said ring relatively to the shank 1.

The form and construction of the chaser dies 50 can be best explained by describing the manner in which they are made. die blanks are in the form of flat cylindrical blocks with a central aperture 51 recessed or counter-sunk onboth sides of the block, and the thread 52 on the cylindrical surface 'of said block is cut as a complete helical thread, left-hand if the die is to cuta righthand thread on the work, and right hand if a left-hand thread is to be cut. The face of the block designed to be directedinwardly, 2'. 6., toward the slide 11, to which the particular die is attached, is formed with radial serrations 53 in order to enable it to be attached and held in proper angular position on such slide, as will be presently explained, and a little hole 54 is drilled, preferably in 'the' same face, to serve as a reference point from which to start such thread in cutting the same. There being four dies employed in the head, located exactly ninety degrees apart, the thread is cut on the blanks, starting at points each successively ninety degrees in advance of the other. Thereupon. by milling off a portion of the threaded faces of such a set of four dies to form the cutting teeth 55 thereon, all the same angular distance with respect to the reference point used in initially cutting such threads, the latter, it will be seen, will present the proper advance. in the case of successive dies. Furthermore. in subsequently milling or grind- .ing'the dies. by grinding them all the same amount. this advance is at all times preserved. The extent of the face milled away rations 53 previously referred to.

The

screw ca n be made.

initially. 5.6., in making a new set of dies, need be only enough to provide the necessary clearance for the heel 56, as indicated by the an ular space between the lines a and Z) in 1 igs. 15 and 16. An intermediate point is indicated by the line 0 in the figures just named, and obviously the face may be ground away, still leaving the cutting threads in proper relation. until the threaded face of the die has been practically used up.

The individual die 50 is secured to its corresponding slide 11 by means of a hardened steel sleeve or thimble 60 set into such slide andformed to fit in the recessed face of such die. which also'beals the radial seri. Set screw 61, the head of which fits into the recess on the opposite side of the die, clamps the latter firmly to the slide. In order accurately to locate and fix the die in proper angular position on the slide, the latter is provided with a block (32 of segmental form that is inset in a recess 63 of corresponding form. and is provided with serrations 64: complementary to those on the juxtaposed side of the die. Set-screws 65 in opposite sidesof the slide enable this block to be mo'ved through a small arc, angularly about the axis of the die in order to permit of proper initial adjustment, so that the cu't ting threads on such die may be brought exactly onto a radial line with respect to the axis of the die-head, as illustrated in Fig. 1.

By reason of the unique construction'of the chaser dies just described. it will be seen that they will cut a thread absolutely true to pitch. irrespective of their 'adial posimay be readily ground, lapped, and otherwise fixed up until as nearly perfect as a The marked utility and practical advantage of the construction accordingly at once becomes apparent. where, as in the case of electrical work. for example. it is necessary to cut threads of the same pitch but on various diameters of stock. The only limitation to the diameter of stock that can be cut with my improved die-head obviously is the size of the head itself. '1'. e. the capacity of the slides for radial adjustment.

The mode of operation of the die-head as a whole may now be set forth. Assuming the dies to be properly fixed on their respec- .lized, and that. after hardening, such threads appropriate adjustment of the knurled annulus 26, which, as previously explained, serves thus to set the dies to cut any desired diameter of threlid within the capacity of the head, the position of parts at starting the cut is shown in Figs. 5, t5 and T. In this position the lugs or ears 3 on the shank 7 engage the forward or narrower portions of the recesses 9 in the body 7, and similarly the pin 45 on the forward end of such shank engages the forward narrower portion of the recess H. as shown in dotted outline in Fig. 12. At the same time the pins 34 on the outer casing 28 of the head are in the extreme forward portions of the angular grooves 21 on the cam ring 17, and the angular projections 25 on the ring 25 attached to such casing at the bottoms of the corresponding angular notches 19 in the rear edge of such cam ring, as shown in Fi 11.

n the condition stated, the parts of the die head are all locked together, and such head may be advanced onto the work, or the work into the head, as the case may be, until the desired length of thread is cut. 'hen this point is reached, and such relative longitudinal movement of the head and work is brought to a stop,.the continued rotation of the work relative to the die-head (or vice versa) will nevertheless cause a further longitudinal advance of the dies onto the work, thus pulling said dies and along therewith the body or barrel of the head, a sutficient distance relatively to the shank to disengage both the ears 3 on such shank from the narrower portions of the respective recesses 9 in the head, wherewith they normally engage, and at the same time disengage the radial pin 45 on the forward end of said shank from the narrower portion of the aperture ll in the body. As a result the latter is left free to rotate within the limits determined by the larger portions of the recesses just referred to. The frictional engagement between the dies and the work will thereupon impart a rotative movement to the body of the head in one direction or the other. depending upon whether a right-hand or lef hand thread is being cut. until the ears 3 and pin it?) come into engagement with the corresponding sides of the larger portions of the recesses 9 and such aperture 44. respectively. in Fig. 2 the position of such ears is that thus assumed, following the cutting of a righthand thread.

incidentally, the pin 4:"). which, it will be recalled. projects through the aperture ll into engagement with the. recess 46 on the inner face of the ring 25. strikes the corresponding edge of such recess and imparts a slight rotative movement to said ring. sullicient to start the angular projections :25 on its forward edge down the adjacent inclined sides of the angular notches 19 in the rear edge of the cam-ring. Thereupon, the springs 41 force a completion of such rotative movement, bringing the cam-ring back to its real-most position, in which the dies are completely retracted. The exteriorly visible effect of the operation just described is the rotation of the ring 25, and, together therewith, of theouter casing 28 of the die-head, which is connected therewith through the medium of the handle 30, from the position indicated by the dotted outline of the latter in Fig. 3 to the position indicated in full lines in said figure.

To reset the die-head for a fresh operation, it is merely necessary to return said ring 25, through the medium of this same handle, from the position indicated by the full line showing of the latter in said Fig. 3, to the position indicated by the dotted outline of the latter. The result of the rotative movement thus imparted to said ring will be again to advance the cam-ring 17 and correspondingly advance the chaser dies. 1'. 0. force them radially inwardly to their normal .or cutting position. In this position of the ring 25 and cam-ring 17, the angular projections 25* rest on the lands between the notches 19 in the rear edge of the cam-ring, the ears 3 on the shank again en gage with the narrower portions of the recesses 9. and the pin 45 on the forward end of said shank drops into the narrower portion of the aperture 44 in the barrel 0: body of the (lie-head.

The actual manipulation of my improved die-head. when in operation, is thus seen to be exceedingly simple, and, as previously pointed out. the adjustment thereof to cut threads of different diameter, so long as the pitch does not require to be changed, requires merely the proper setting of the knurled annulus 26. All of the operative parts of the head are incased so as to be secure against the entrance of dust or grit, which might either cause wear or affect the smoothness of the operation of the head. The opening of the dies is not only automatic. but follows practically instantaneously upon the completion of the cut. Fi-

llltl llllti nally. the construction and mounting of the the combination of a body; chaser dies mounted in said body; a ring movable longitudinally of said body and operatively connected with said dies variously to position the same; a second ring rotatably' mounted on said body, said first and second rings having cooperative cam-faces whereby rotation of said second serves to move said first longitudinally of said body,- and'a cylindrical casing surrounding both rings and being fixedly attached to said second ring and having positioning connection with said first ring.

2. In a device of the character described, the combination of a body; chaser dies mounted in said body; a ring movable longitudinally of said body and operatively connected with said dies variously to position the same; a second ring rotatably mounted on said body, said first and second rings having cooperative cam-faces whereby rotation of said second serves to move said first longitudinally of said body, a cylindrical casing surrounding both rings and being fixedly attached to said second ring and having positioning connection with said first ring, and means to variously position said casing normally on said body.

3. In a device of the character described the combination of a body; chaser dies mounted in said body; a ring movable longitudinally of said body and operatively connected with said dies variously to position the same; a second ring rotatably mounted on said body, said first and second rings having cooperative cam-faces whereby rotation of said second serves to move said first longitudinally of said body, a cylindrical casing Surrounding both rings and being fixedly attached to said second ring and having positioning connection with said first ring, and means to adjust said casing longitudinally of said body to vary the normal position of said first ring and thus of said dies.

i. In a device of the character described, the combination of a body; chaser dies mounted on said body; a ring movable longitudinally of said body and having an inwardiy directed cone-surface engaging with said dies variously to position the same, the rear edge of said ring being formed with a series of angular notches and its outer surface with corresponding angular grooves; a second ring rotatably mounted on said body and formed with a complementary series of projections engaging such rear edge of said first ring; and a cylindrical casing surrounding both rings, said casing being fixedly attfi'tached to said second ring and having in wardly projecting pins engaging the grooves in said first ring.

5. In a device of the character described, the combination of a body; chaser dies 65 mounted on said body; a ring movable longitudinally of said body and having an inwardly directed cone-surface engaging with said dies variously to position the same, the rear edge of said ring being formed with a series of angular notches and its outer surface with corresponding angular grooves; a second ring rotatably mounted on said body and formed with a complementary series of projections engaging such rear edge of said first ring; a cylindrical casing surrounding both rings, said casing being fixedly attached to said second ring and having inwardly projecting pins engaging the grooves in said first ring; and an annulus threaded on said body and adapted to adjust the position of said casing longitudinally of said body.

6. In a device of the character described, the combination of a body; chaser dies mounted on said body; a ring movable longitudinally of said body and having an inwardly directed cone-surface engaging with said dies variously to position the same, the

rear edge of said ring being formed with a series of angular notches and its outer surface with corresponding angular grooves; a second ring rotatably mounted on said body and formed with a complementary series of projections engaging such rear edge of said first ring; a cylindrical casingv surrounding both rings, said casing being fixedly attached to said second ring and having inwardly projecting pins engaging the grooves in said first ring; and springs in said body tending to hold said first ring in contact with said second ring.

v 7. In a device of the character described, the combination or a shank; a-bodyhaving limited rotative and longitudinal movement on said shank; chaser dies mounted on said body; a ring movable longitudinally of said body and operatively connected with said dies to variously position the same; a second ring rotatably mounted on said body and operatively connected to said first ring to move the same longitudinally of said body; and means on said shank'limiting r0. tative movement of said second ring relatively thereto. a

8. In a device of the character described, the combination of a shank having a radial projection; a body rotatably and longitudinally'movable on said shank, said body being formed with a longitudinally extending recess adapted to receive such projection and wider at one end than thevother, whereby said body is held against rotation relatively to said shank when said projection is in the narrower portion of such recess and is capable of limited rotation when said projection is in the wider portion of such recess; a ring movable longitudinally of said body and operatively connected with said dies to variously position the same; a second ring rotatably mounted on said body and operatively connected to said first ring to move the same longitudinally of said body; and means on said shank limiting rotative move nent of said second ring relatively theret 9. In adevice of the character described, the combination of ashank having a radial projection: a body rotatably and longitudinally mo *able on said shank. said body being formed with a longitudinally extending recess adapted to receive such projection and wider at one end than the other, whereby said body is held against rotation relatively to said shank when said projection is in the narrower portion of such recess and is capable of limited rotation when said projection is in the wider portion of such recess; a ring movable longitudinally of said body and operatively connected with said dies to variously position the same; a second ring rotatably mounted on said body and operatively connected to said first ring to move the same longitudinally of said body; and an extension on the aforesaid projection adapted to engage said second ring and limit rotation thereof relatively to said shank.

10. In a device of the character described, the combination of a shank having a radial projection; a body rotatably and longitudinally mo able on said shank. said body being formed with a longitudinally extending recess adapted to receive such projection and wider at one end than the other, whereby said body is held against rotation relatively to said shank when said projection is in the narrower portion of such recess' and is capable of limited rotation when said projection is in the wider portion of such recess; a ring movable longitudinally of said body and operatively connected with said dies to variously position the same; a second ring rotatably mounted on said body and operatively connected to said first ring to move the same longitudinally of said body; springs in said body tending to hold said first ring in contact with said second ring; and an extension on the aforesaid projection adapted to engage said second ring and limit rotation thereof relatively to said shank.

11. In a device of the character described. the combination of a shank having a radial projection; a body rotatably and longitudinally movable on said shank, said body being formed with a longitudinally extending recess adapted to receive such projection and wider at one end than the other. whereby said body is held against rotation relatively to said shank when said projection is in the narrower portion of such recess and is capable of limited rotation when said projection is in the wider portion of such recess; a ring movable longitudinally of said body and operatively connected with said dies to variously position the same: a second ring rotatably mounted on said body and operatively connected to said first ring to move the same longitudinally of said body; an annulus threaded on said body and adapted to adjust .the position of said second ring longitudinally of the same; springs on said body tending to hold said first ring in contact with said second ring; and an extension on the aforesaid projection adapted to engage said second ring and limit rotation thereof relatively to said shank.

Signed by me, this 16th day of October, 1918.

VILLIAM C. HAFEMEISTER. 

